Stewart-Jones A, Hodges R J, Birkinshaw L A, Hall D R
Natural Resources Institute, University of Greenwich Chatham Maritime, Kent ME4 4TB, United Kingdom.
J Chem Ecol. 2004 Aug;30(8):1629-46. doi: 10.1023/b:joec.0000042073.92464.7d.
Teretrius nigrescens is considered to be a specialized predator of Prostephanus truncatus, a serious pest of stored maize and dried cassava roots. Using a bait-bag behavioral bioassay, this investigation found T nigrescens to be strongly arrested by dust and frass produced by P. truncatus on maize, whereas responses to maize flour were weak. Attempts to increase the arrestiveness of flour by altering its physical properties (coarseness or particle size range) were unsuccessful. The arrestive property of dust/frass did not degrade with long-term storage nor did it volatilize or degrade with oven baking up to 150 degrees C. However, extraction with methanol and reapplication was successful in transferring the arrestive property from the dust/frass onto maize flour. The prey dust/frass also induced more oviposition than did maize flour, as judged by production of F1 offspring. The results provide strong evidence for the existence of a high boiling point compound(s) in P. truncatus dust/frass that acts as a contact kairomone for T nigrescens. This, or another compound(s) also seems to act as an oviposition stimulant for female T. nigrescens.
暗黑圆蛛被认为是截尾长蠹的一种专门捕食者，截尾长蠹是储存玉米和干木薯根的一种严重害虫。通过诱饵袋行为生物测定，本研究发现暗黑圆蛛会被截尾长蠹在玉米上产生的灰尘和粪便强烈吸引，而对玉米粉的反应则较弱。试图通过改变玉米粉的物理性质（粗糙度或粒度范围）来提高其吸引力的尝试并未成功。灰尘/粪便的吸引特性不会因长期储存而降低，也不会在高达150摄氏度的烤箱烘烤下挥发或降解。然而，用甲醇提取并重新应用成功地将吸引特性从灰尘/粪便转移到了玉米粉上。根据F1代后代的产生情况判断，猎物的灰尘/粪便比玉米粉诱导的产卵更多。这些结果为截尾长蠹灰尘/粪便中存在一种高沸点化合物提供了有力证据，该化合物作为暗黑圆蛛的接触性利它素起作用。这种或其他化合物似乎也作为暗黑圆蛛雌蛛的产卵刺激物起作用。
